1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 // Deliberately overwrite the stack canary. 18 __attribute__((noinline)) void modify_stack_protector_test() { 19 char buf[128]; 20 // We can't use memset here because it's fortified, and we want to test 21 // the line of defense *after* that. 22 // Without volatile, the generic x86/x86-64 targets don't write to the stack. 23 volatile char* p = buf; 24 int size = static_cast<int>(sizeof(buf) + 1); 25 #if __x86_64__ 26 // The generic x86-64 target leaves an 8-byte gap between `buf` and the stack guard. 27 // We only need to corrupt one byte though. 28 size += 8; 29 #endif 30 while ((p - buf) < size) *p++ = '\0'; 31 } 32
